Package org.datanucleus.metadata

Provides classes representing the MetaData for files, packages, classes, fields, containers, etc.

See: Description

Interface Summary

Interface	Description
ColumnMetaDataContainer	Interface defining an object that contains Columns.
MetaDataListener	Listener for registering interest when metadata for a class is loaded.
MetaDataManager	Manager for metadata in DataNucleus.
MetaDataScanner	Scanner for persistable classes, typically provided by a JEE environment to locate classes not easily/efficiently locatable using the builtin file scanner.

Class Summary

Class	Description
AbstractClassMetaData	Abstract representation of the MetaData of a class/interface.
AbstractElementMetaData	This element specifies the mapping for the element component of arrays and collections.
AbstractMemberMetaData	Abstract representation of MetaData for a field/property of a class/interface.
ArrayMetaData	Representation of the Meta-Data for an Array.
ClassMetaData	Representation of the MetaData of a class.
CollectionMetaData	Representation of the MetaData of a collection.
ColumnMetaData	Representation of the Meta-Data for a column mapping of a field.
ConstraintMetaData	Representation of an ORM constraint.
ContainerMetaData	Representation of the Meta-Data for a container.
DiscriminatorMetaData	Representation of a discriminator in an inheritance strategy.
ElementMetaData	This element specifies the mapping for the element component of arrays and collections.
EmbeddedMetaData	This element specifies the mapping for an embedded type.
EventListenerMetaData	Listener for events, following the JPA model.
FetchGroupMemberMetaData	Metadata for a member of a fetch group
FetchGroupMetaData	A fetch group defines a particular loaded state for an object graph.
FetchPlanMetaData	FetchPlan defined in MetaData.
FieldMetaData	Representation of the Meta-Data for a field of a class.
FileMetaData	Representation of a Meta-Data file.
ForeignKeyAction	Foreign keys represent a consistency constraint in the database that must be maintained.
ForeignKeyMetaData	Foreign keys in metadata serve two quite different purposes.
IdentityMetaData	Meta-Data for the datastore-identity of a class.
ImplementsMetaData	The implements element declares a persistence-capable interface implemented by the persistence-capable class that contains this element.
IndexMetaData	For schema generation, it might be useful to specify that a column or columns be indexed, and to provide the name of the index.
InheritanceMetaData	Representation of the Meta-Data defining inherited classes.
InterfaceMetaData	Representation of the MetaData of a "persistent-interface".
JoinMetaData	Secondary tables and join tables are mapped using a join condition that associates a column or columns in the secondary or join table with a column or columns in the primary table, typically the primary tables primary key columns.
KeyMetaData	This element specifies the mapping for the key component of maps.
MapMetaData	Representation of the Meta-Data for a Map.
MetaData	Base class for all MetaData.
MetaDataManagerImpl	Manager of metadata information in DataNucleus having scope of an NucleusContext.
MetaDataMerger	Convenience class to handle the merging of MetaData.
MetaDataUtils	Utilities needed for the processing of MetaData.
OrderMetaData	Representation of Order MetaData - the ordering of the elements of a List.
OrderMetaData.FieldOrder	Definition of ordering using a field.
PackageMetaData	Representation of the Meta-Data for a package.
PersistenceFileMetaData	Representation of a Meta-Data "persistence.xml" file.
PersistenceUnitMetaData	MetaData representation of a "persistence.xml" persistence unit.
PrimaryKeyMetaData	Representation of a primary key constraint.
PropertyMetaData	The property element declares mapping between a virtual field of an implemented interface and the corresponding persistent field of a persistence-capable class.
QueryMetaData	Representation of the MetaData of a named Query.
QueryResultMetaData	Representation of the mapping of (SQL) Query results into a desired output form.
QueryResultMetaData.ConstructorTypeColumn
QueryResultMetaData.ConstructorTypeMapping	Class to wrap the mapping for a constructor type.
QueryResultMetaData.PersistentTypeMapping	Class to wrap the mapping for a persistent type.
SequenceMetaData	Representation of the MetaData of a named Sequence (JDO, or JPA).
StoredProcQueryMetaData	Metadata representation of a named stored proc query.
StoredProcQueryParameterMetaData	Metadata representation of a parameter for a named stored proc query.
TableGeneratorMetaData	Representation of the MetaData of a TableGenerator (JPA).
UniqueMetaData	MetaData representing a unique constraint.
ValueGenerationStrategy	Value generation "strategy".
ValueMetaData	This element specifies the mapping for the value component of maps.
VersionMetaData	Three common strategies for versioning instances are supported by standard metadata.

Enum Summary

Enum	Description
ClassPersistenceModifier	Definition of the options for persistence-modifier of a class.
DiscriminatorStrategy	Representation of the values for discriminator "strategy".
FieldPersistenceModifier	Class defining the possibilities for persistence, in terms of the type of persistence, and the types that are capable to be supported.
FieldRole	Series of roles that fields can be performing in the (ORM) mapping process.
IdentityType	Representation of the values for identity-type.
IndexedValue	Representation of whether an item is indexed or not.
InheritanceStrategy	Representation of the values for inheritance "strategy".
JdbcType	Representation of the jdbc-type of a column.
MapMetaData.MapType
MetadataFileType	Enum for the different types of metadata "files".
NullValue	Representation of how to handle a null value (in a field).
QueryLanguage	Representation of the primary query languages.
RelationType	Utility class providing enums for the different relation types.
SequenceStrategy	Representation of strategy of a Sequence.
StoredProcQueryParameterMode	Mode of usage of a stored procedure query parameter.
TransactionType	Representation of a transaction type.
VersionStrategy	Three common strategies for versioning instances are supported by standard metadata.

Exception Summary

Exception	Description
InvalidAnnotationException	Exception thrown when an annotation has been specified that is invalid in the circumstances.
InvalidClassMetaDataException	Exception thrown when meta-data specific to a class is invalid.
InvalidMemberMetaDataException	Exception thrown when meta-data specific to a member of a class is invalid.
InvalidMetaDataException	Representation of an exception thrown when an error occurs in Meta-Data definition.
InvalidPrimaryKeyException	Exception thrown when a primary key class is found to be invalid for some reason.

Package org.datanucleus.metadata Description

Provides classes representing the MetaData for files, packages, classes, fields, containers, etc. Structured to map to the JDO2 Meta-Data file structure, though also now maps to the JPA Meta-Data structure approximately.

Key aspects of this package are

• MetaDataManager is the entry point into this package. A call is typically made to getMetaDataForClass and the MetaDataManager will take care of finding the MetaData, parsing any files, and populating the MetaData.
• MetaDataMerger is responsible for merging annotations with metadata, and JDO MetaData with ORM MetaData
• FileMetaData is the top level of a metadata representation, represening the actual file. It will contain metadata for a series of packages, etc. The components are laid out in a tree
• ClassMetaData is the most used class, and is the representation of the persistence of a class. It contains a series of FieldMetaData/PropertyMetaDataobjects, representing the fields and properties of the class.

The "data" classes have a lifecycle, being created, then populated, and finally initialised. When a file is read in all classes are read and populated at that time.